Starting your own sourdough starter actually begins with creating your own wild yeast culture. It may take a little time, care, and attention, but the results are well worth it in the end! 

Preparation

Day 1: Create a Yeast Culture

Mix ½ cup whole wheat flour and ½ cup bread flour with 1 cup cool water until the flours are completely incorporated. Cover and let rest for 2 days. 

Note: During all rest periods, culture should be stored at room temperature (60–70°F).

Day 3 : Refresh the Environment

Discard half of the culture. Add ½ cup whole wheat flour, ½ cup bread flour, and 1 cup of cool water to remaining culture, then stir until ingredients are fully incorporated. Cover and let rest for 2 days. 

Day 5: Increase the Starter Volume

Add 1 cup room temperature water to the culture, then add 1 cup bread flour and stir until flour is completely incorporated. Cover and let rest for 24 hours.

Day 6: Standardize the Starter Volume

Discard half of the culture. Add ¾ cup water to the remaining culture, then add 1 cup bread flour and stir until ingredients are incorporated. Cover and let rest for 24 hours.

Day 7–14: Start & Repeat Routine Feeding

Repeat Day 6 steps.

Day 15+: Keep the Culture Alive

Congratulations! Your starter is now a wild yeast culture just like the first bakers used thousands of years ago. To keep your culture ripe and sustain it for the long haul, follow these steps in perpetuity:

1. Divide: Use ⅔ of the culture to bake with and reserve ⅓ of the culture to propagate. Bring culture to room temperature before using.
2. Feed: Replenish the culture every other week with 5 parts water and 4 parts bread flour by weight.
3. Ferment: Let culture ferment for 2 hours at room temperature, then store in refrigerator for 8–24 hours or more to preserve and slow fermentation.